The invention relates to a portable containment device for hazardous chemicals such as agricultural chemicals, and the like, and the prevention of ground water contamination by the chemicals. Ground water contamination is the long-term result of point source spills and application of long-term residual water-dispersible, general use pesticides and other hazardous or toxic chemicals. These spills result from mixing, loading, and unloading, clean-up, and disposal of chemicals and the like. States regulate commercial bulk pesticide storage locations and commercial mixing and loading sites. However, the current containment regulations are directed towards fixed base location sites. Regulations have not been directed to field mixing and loading sites due to cost and compliance problems. In particular, the problem of loading and offloading pesticides during applications at on-site farm field locations and preventing ground water contamination is a problem to which considerable attention need be given. In handling the toxic chemicals, pesticides, and the like, it is necessary to contain the chemicals in case of a spill to prevent contact with the surrounding environment. In the handling of pesticides in large volumes, it is necessary to prevent spills of the pesticides from being absorbed in the soil and eventually contaminating water systems. For example, in agricultural use, toxic chemicals are often loaded from tank truck vehicles to or from agricultural spraying airplanes or other application vehicles. In the transfer of the chemicals, spills can occur and it is necessary to prevent the spill from absorption in the soil.
In the past, temporary, disposable, or stationary containments have been provided in which a plastic membrane or fabric which contains the chemical is supported by air inflatable walls or foam for containing the chemical. U.S. Pat. No. 4,671,024 discloses a disposable drip pan for use under a vehicle which contains dirt or other matter and to prevent the same from soiling or contaminating a floor surface at a fixed site. Air inflated sleeves or radially compressible pipe tubing form a ridge which surrounds a floor of the drip pan to contain material falling off the vehicle. While a vehicle may be driven over the ridge, the ridge is not sufficient for containing liquid spills, such as agricultural chemicals, in large volumes, nor is it fastened to the floor to prevent dislocation by prop wash from aircraft. The corners are not designed to withstand impact from vehicle traffic. Similar temporary containment systems are known which may be folded, assembled, inflated, and transported having a rubberized fabric which withstands rough treatment and a broad range of chemicals. However, again, the support tubes for the side walls are inflatable with air are susceptible to puncture and are separate pieces that require assembly. With the side walls inflated, considerable risk is involved when driving a vehicle on or off the containment, and the walls must be removed to allow vehicle traffic. To deflate the walls permits liquid to escape the containment.
Accordingly, an object of the invention is to provide a portable containment unit which is economical, portable, and easy to transport and deploy, and which may be reused.
Another object of the invention is to provide a portable containment unit for containing hazardous chemicals and the like which is truly portable in that it may be folded, transported, and reused at different sites without disassembly or reassembly being required.
Another object of the invention is to provide a portable containment unit for the prevention of ground spills which is highly durable and can withstand vehicle traffic onto and off of the unit without altering the unit.
Another object of the invention is to provide a portable containment unit which is portable, requires no assembly at the site, can withstand vehicle traffic over the walls of the containment unit, and can tolerate toxic chemicals such as pesticide solutions.
Another object of the invention is to provide a portable containment unit having all of the above described features which can be reused in the field or at air strips for agricultural pesticide application when loading or unloading aircraft, vehicles, or similar industrial use.